Base station for wireless digital telephone system

• US 4,777,633 A
• Filed: 08/14/1987
• Issued: 10/11/1988
• Est. Priority Date: 08/14/1987
• Status: Expired due to Term

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: International Mobile Machines Corporation (InterDigital, Inc.)
• Inventors: Fletcher, Thomas E., Avis, Wendeline R., Saffee, Gregory T., Johnson, Karle J.
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): Marcelo, Melvin
• Application Number:
  US07/071,279
• Time in Patent Office: 424 Days
• Field of Search: 370/109, 370/97, 370/95, 370/93, 370/50, 379/56, 379/59, 379/63, 455/33, 455/54, 455/56, 455/69
• US Class Current: 370/345
• CPC Class Codes: H04J 3/0691 Synchronisation in a TDM node
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 88/08 Access point devices
• CPC Class Codes: H04W 92/12 between access points and access point controllers

Abstract

A base station for use in a subscriber communication network for communicating signals between subscriber stations and an external communication network having a plurality of ports includes a communication circuit for enabling simultaneous communications between a plurality of the ports and a plurality of the subscriber stations over a given communication channel having multiple sequentially repetitive time slots; an exchange for connecting the communication circuit to the external communication network ports; and a remote-connection processor coupled to the communication circuit by the exchange and by a base-station control channel occupying a selected one of the time slots for monitoring the status of the other time slots and for causing the communication circuit and the exchange to complete a connection between a given external communication network port and a given subscriber station over a time slot assigned in response to the monitored status in accordance with a predetermined assignment routine.

Claims

1. A base station in a subscriber communication network for communicating signals between subscriber stations and an external communication network having a plurality of ports, comprising

a communication circuit including

a trunk for providing a communication channel and

a multiplexer coupled to the trunk for providing multiple sequentially repetitive time slots in the communication channel for enabling simultaneous communications between a plurality of the ports and a plurality of the subscriber stations over the communication channel;

an exchange for connecting the trunk to the external communication network ports; and

a remote-connection processor coupled to the trunk in the communication circuit by a base-station control channel and to the exchange for monitoring the status of the time slots and for causing the communication circuit and the exchange to complete a connection between a given external communication network port and a given subscriber station over a time slot assigned in response to said monitored status in accordance with a predetermined assignment routine;

wherein the communication circuit further comprises

a plurality of channel control units coupled to the multiplexer for coupling assigned time slots to given subscriber stations and

a plurality of communication signal processors coupled to given subscriber stations by the channel control units in response to command signals from the remote-connection processor, wherein the communication signal processors are respectively coupled by the multiplexer to predetermined time slots of the communication channel carried over the trunk, and each communication signal processor provides a predetermined signal pattern in its predetermined time slot when not coupled by its channel control unit to the remoteconnection processor;

wherein the exchange is responsive to a command from the remote-connection processor for causing a signal received by the exchange from one of the communication signal processors over a given time slot to be looped back to the communication signal processor coupled to that time slot; and

wherein each communication signal processor is coupled to one of the channel control units for enabling the coupled channel control unit in response to said looped-back predetermined signal pattern to receive commands from the remote-connection processor for assigning the communication signal processor that receives the looped-back predetermined signal pattern to communicate with a given subscriber station.

2. A base station according to claim 1,

wherein the remote-connection processor means for assigning a given time slot to a given subscriber station, said assigning means including

means for commanding the exchange to loop back signals received from the communication signal processor coupled to the given time slot;

means for sending an address initialization signal over the base-station control channel to all of the channel control units to store an address associated with the given subscriber station in the channel control unit that is enabled in response to the communication signal processor coupled thereto receiving said looped-back predetermined signal pattern; and

means for commanding the channel control unit in which the address is stored to assign the given-time-slot-coupled communication signal processor to the given subscriber station.

3. A base station according to claim 2,

wherein each channel control unit includes means for responding to storage of a said address by sending an acknowledgement to the remote-connection processor;

and

wherein the remote-connection processor further includes means for commanding the exchange to loop back signals received from the communication signal processor coupled to a different given time slot when no acknowledgement is received from the channel control unit coupled to the communication signal processor coupled to the first-recited given time slot.

4. A base station in a subscriber communication network for communicating signals between subscriber stations and an external communication network having a plurality of ports, comprising

a communication circuit including

a trunk for providing a communication channel and

a multiplexer coupled to the trunk for providing multiple sequentially repetitive time slots in the communication channel for enabling simultaneous communications between a plurality of the ports and a plurality of the subscriber stations over the communication channel;

an exchange for connecting the trunk to the external communication network ports; and

a remote-connection processor coupled to the trunk in the communication circuit by a base-station control channel (BCC), which occupies one of the time slots, and to the exchange for monitoring the status of the time slots for causing the communication circuit and the exchange to complete a connection between a given external communication network port and a given subscriber station over a time slot assigned in response to said monitored status in accordance with a predetermined assignment routine;

wherein the communication circuit further comprises

a plurality of channel control units coupled to the multiplexer for coupling assigned time slots to given subscriber stations; and

wherein one of the channel control units communicates control signals between the BCC and all of the subscriber stations over a radio control channel allocated to a given time slot of a given frequency channel by the remote-connection processor in response to said monitored status in accordance with a predetermined allocation routine in which the first priority is given to the time slot of the radio frequency channel that is coincident with the time slot occupied by the base-station control channel.

5. A base station in a subscriber communication network for communicating signals between subscriber stations and an external communication network having a plurality of ports, comprising

a communication circuit including

a plurality of trunks for providing a plurality of communication channels and

a plurality of multiplexers coupled to the plurality of trunks for providing multiple sequentially repetitive time slots in each of the communication channels for enabling simultaneous communications between a plurality of the ports and a plurality of the subscriber stations over the communication channels;

an exchange for connecting the trunks to the external communication network ports; and

a remote-connection processor coupled to the trunks in the communication circuit by a base-station control channel (BCC), which occupies one of the time slots, and to the exchange for monitoring the status of the time slots and for causing the communication circuit and the exchange to complete a connection between a given external communication network port and a given subscriber station over a time slot assigned in response to said monitored status in accordance with a predetermined assignment routine;

wherein the communication circuit further comprises

a plurality of channel control units coupled to the multiplexers for coupling assigned time slots to given subscriber stations;

a plurality of controllers respectively coupled to the multiplexers and

a local bus between the controllers and the channel control units; and

wherein, in accordance with said monitored status, the remote-connection processor selects one of the time slots to carry the base-station control channel and causes the controller that is coupled to the multiplexer that is coupled to the trunk that carries the time slot selected to carry the base-station control channel to function as a primary controller for coupling the base-station control channel over the local bus to the other controllers and to the channel control units for enabling the remote-connection processor to monitor the status of the other time slots and to assign the other time slots.

6. A base station according to claim 5,

wherein the communication circuit includes a plurality of communication signal processors coupled to given subscriber stations by the channel control units in response to command signals from the remote-connection processor, wherein the communication signal processors are respectively coupled by the multiplexers to predetermined time slots of predetermined communication channels carried over the trunks, and each communication signal processor provides a predetermined signal pattern in its predetermmined time slot when not coupled by its channel control unit to the remote-connection processor;

wherein the exchange is responsive to a command from the remote-connection processor for causing a signal received by the exchange from one of the communication signal processors over a given time slot to be looped back to the communication signal processor coupled to that time slot; and

wherein each communication signal processor is coupled to one of the channel control units for enabling the coupled channel control unit in response to a said looped-back predetermined signal pattern to receive commands from the remote-connection processor for assigning the communication signal processor that receives the looped-back predetermined signal pattern to communicate with a given suscriber station.

7. A base station according to claim 6,

wherein the remote-connection processor comprises means for assigning a given time slot to a given subscriber station, said assigning means including

means for commanding the exchange to loop back signals received from the communication signal processor coupled to the given time slot;

means for sending an address initialization signal over the base-station control channel to all of the channel control units to store an address associated with the given subscriber station in the channel control unit that is enabled in response to the communication signal processor coupled thereto receiving said looped-back predetermined signal pattern; and

means for commanding the channel control unit in which the address is stored to assign the given-time-slot coupled communication signal processor to the given subscriber station.

8. A base station according to claim 7,

wherein each channel control unit includes means for responding to storage of a said address by sending an acknowledgement to the remote-connection processor;

and

wherein the remote-connection processor further includes means for commanding the exchange to loop back signals received from the communication signal processor coupled to a different given time slot when no acknowledgement is received from the channel control unit coupled to the communication signal processor coupled to the first-recited given time slot.

9. A base station according to claim 5, wherein one of the channel control units communicates control signals between the BCC and all of the subscriber stations over a radio control channel allocated to a given time slot of a given frequency channel by the remote-connection processor in response to said monitored status in accordance with a predetermined allocation routine in which the first priority is given to the time slot of the radio frequency channel that is coincident with the time slot occupied by the base-station control channel.

10. A base station according to claim 5, wherein the multiplexers and the channel control units are modular for enabling their addition to and removal from the system in accordance with changes in the number of subscriber stations with which the base station communicates.

11. A base station in a subscriber communication network for communicating signals between subscriber stations and an external communication network having a plurality of ports, comprising

a communication circuit including

a plurality of trunks for providing a plurality of communication channels and

a plurality of multiplexers coupled to the plurality of trunks for providing multiple sequentially repetitive time slots in each of the communication channels for enabling simultaneous communications between a plurality of the ports and a plurality of the subscriber stations over the communication channels;

an exchange for connecting the trunks to the external communication network ports; and

a remote-connection processor coupled to the trunks in the communication circuit by a base-station control channel and to the exchange for monitoring the status of the time slots and for causing the communication circuit and the exchange to complete a connection between a given external communication network port and a given subscriber station over a time slot assigned in response to said monitored status in accordance with a predetermined assignment routine;

wherein the communication circuit further comprises

a plurality of channel control units coupled to the multiplexers for coupling assigned time slots to given subscriber stations, with each channel control unit coupling a plurality of assigned time slots to a corresponding plurality of subscriber stations;

wherein said assignment routine includes assigning all of the time slots associated with a given channel control unit before assigning time slots associated with another channel control unit, and then assigning time slots associated with a channel control unit coupled to a different multiplexer than the multiplexer coupled to the channel control unit associated with the immediately previously assigned time slots.

12. A base station in a subscriber communication network for communicating signals between subscriber stations and an external communication network having a plurality of ports, comprising

a communication circuit including

a trunk for providing a communication channel and

a multiplexer coupled to the trunk for providing multiple sequentially repetitive time slots in the communication channel for enabling simultaneous communications of digital information signals between a plurality of the ports and a plurality of the subscriber stations over the communication channel;

an exchange for connecting the trunk to the external communication network ports; and

a remote-connection processor coupled to the trunk in the communication circuit by a base-station control channel and to the exchange for monitoring the status of the time slots and for causing the communication circuit and the exchange to complete a connection between a given external communication network port and a given subscriber station over a time slot assigned in response to said monitored status in accordance with a predetermined assignment routine;

wherein the communication circuit further comprises

a plurality of channel control units coupled to the multiplexer for coupling assigned time slots to given subscriber stations via radio frequency channels and

a plurality of channel control units coupled to given subscriber stations by the channel control units in response to command signals from the remote-connection processor, wherein the communication signal processor are respectively coupled by the multiplexer to predetermined time slots of the communication channel carried over the trunk and by the channel control units to given time slots of the radio frequency channels.

13. A base station according to claim 12,

wherein the exchange comprises a concentrator.

14. A base station according to claim 12,

wherein means are provided to decrease jitter and to control slips in the received signals, said means comprising a frame buffer containing a plurality of frames

wherein a selected address within each frame corresponds to a selected channel assignment, said frames having an initial predetermined separation.

15. A base station according to claim 12, further comprising

an echo canceller for cancelling echoes in voice signals communicated over the trunk;

wherein the remote-connection processor is coupled to the echo canceller for enabling the operation of the echo canceller during only those time slots that have been assigned by the remote-connection processor to carry voice signals.